Posterior tibial slope considered as an important addition to the CPAK classification system.

Introduction: Coronal Plane Alignment of the Knee (CPAK), is an informative way to classify native knee alignment types, but does not consider posterior tibial slope, an important variable in knee kinematics. We hypothesized that tibial slope would have a significant effect on knee kinematics and warrant consideration in addition to the CPAK system. Methods: We examined 335 adult patients with osteoarthritis receiving total knee arthroplasty. We measured the lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and posterior tibial slope angle (PTS). Knees were categorized into CPAK classes and subdivided into types 'A' (PTS 8°) or 'B' (PTS >8°). We recorded pre-and-post operative knee flexion, and extension/flexion gaps in all subjects. Results: CPAK classes VII-IX were not seen. Classes I and II comprised a plurality of all knees. One-third of all knees were type B. CPAK classes III, IV, and VI had greater type B proportions, but this was not statistically significant. Type B knees had greater flexion both pre-op (p < .001) and post-op (p = .043); type A knees had greater flexion improvement pre-to-post operatively (p = .045). Type A knees had greater medial and lateral flexion-extension gap change pre-operatively (p = .021) and (p = .027), respectively. Type B knees had greater medial-lateral gap imbalance preoperatively in both flexion and extension. Discussion/conclusion: Our results suggest that there are important pre and post-operative differences in medial and lateral femorotibial gap balance between type A and B knees that require consideration for intra-operative balancing. Differences in knee flexion further solidify that PTS is an important variable that affects kinematics before and after TKA. We propose the addition of PTS types A and B to the existing CPAK classes. This is an easy and logical way to create a comprehensive classification system in both coronal and sagittal planes that captures further differences in knee kinematics.

Transition to Robotic Total Knee Arthroplasty With Kinematic Alignment is Associated With a Short Learning Curve and Similar Acute-Period Functional Recoveries.

Background Robotic instruments are increasingly being used in total knee arthroplasty (TKA). The adoption of robotics has allowed surgeons a new level of precision and facilitated the adoption of a kinematic approach in TKA. We sought to examine one surgeon's transition from a traditional mechanical alignment technique to a modified kinematic approach by comparing short-term recovery outcomes of robotic TKA patients with those who underwent traditionally instrumented TKAs. Methodology We examined six-week and six-month postoperative data from 99 traditionally instrumented, mechanically aligned and 66 kinematically aligned robotic TKA patients between January 2021-October 2021 and October 2021-April 2022, respectively. Robotic surgery was performed with VELYS™ (DePuy Synthes, Warsaw, IN, USA) a semi-active, imageless, table-affixed, robotic TKA solution. Results Robotic and traditionally instrumented TKAs did not differ significantly in any functional outcome measures examined, including pain scores, use of assistive devices, or range of motion at six weeks postoperatively. Robotic TKA patients had a better range of motion in knee flexion than traditional TKA patients at six months postoperatively. There were no differences in surgical complications or rates of manipulation under anesthesia within one year postoperatively. Robotic surgery tourniquet times exhibited a steep drop off and equaled traditional methods after only two robotic surgeries were performed. Conclusions Transition to a kinematic, semi-active, robotic TKA demonstrated encouraging results by demonstrating acute-period recovery of function consistent with the current standard of care, as well as a better range of motion at six months postoperatively. The learning curve of this new-to-market device was shorter than previous research on the transition to robotic TKA. Clear advantages of transitioning to robotic instrumentation by any specific functional measure are yet to be elucidated. Further randomized trials are necessary to characterize long-term outcomes.

Same-Day Outpatient Lower-Extremity Joint Replacement: A Critical Analysis Review.

➢ The economics of transitioning total joint arthroplasty (TJA) to standalone ambulatory surgery centers (ASCs) should not be capitalized on at the expense of patient safety in the absence of established superior patient outcomes. ➢ Proper patient selection is essential to maximizing safety and avoiding complications resulting in readmission. ➢ Ambulatory TJA programs should focus on reducing complications frequently associated with delays in discharge. ➢ The transition from hospital-based TJA to ASC-based TJA has substantial financial implications for the hospital, payer, patient, and surgeon.

The Impact of Total Hip Arthroplasty Surgical Approach on Patient-Reported Outcomes Measurement Information System Computer Adaptive Tests of Physical Function and Pain Interference.

BACKGROUND: The present study examines Patient Reported Outcomes Measurement Information System (PROMIS) Computer Adaptive Test (CAT) scores for domains of physical function (PF) and pain interference (PI) in patients undergoing elective THA from either a direct anterior or posterior surgical approach. METHODS: A total of 1358 patients who underwent THA at our institution from 1/1/2015 to 12/1/2018 were identified. Visual analog scale (VAS) pain scores, PROMIS CAT PF and PI data were collected at the last preoperative visit as well as 6 weeks, 6 months, and 1-2 years postoperatively. Literature-derived minimum clinically important difference (MCID) for PROMIS CAT PF metric with regard to THA was used for data comparison. RESULTS: Four hundred nine patients were included in the final analysis. Fifty-one percent underwent a posterior approach, and 49% underwent a direct anterior approach. Both approaches led to a significant improvement in PROMIS CAT PF and PI scores. Patients undergoing a direct anterior approach had significantly higher preoperative and postoperative PROMIS CAT PF scores as well as significantly lower preoperative PROMIS CAT PI scores. Each approach yielded similar interval improvements of PROMIS CAT PF and PI. One hundred three direct anterior approach THA patients (51%) and 119 posterior approach THA patients (57.5%) achieved PROMIS PF MCID at 1- to 2-year follow-up. CONCLUSION: Neither the direct anterior nor posterior THA surgical approach conferred an advantage to postoperative improvements of PROMIS CAT PF and PI scores. Adult reconstructive surgeons should continue to execute the direct anterior or posterior THA surgical approaches based upon personal preference. Despite surgeon confidence in THA, the potential for further innovation exists given the number of THA patients who failed to achieve PROMIS PF MCID.

Suppressive Effects of Insulin on Tumor Necrosis Factor-Dependent Early Osteoarthritic Changes Associated With Obesity and Type 2 Diabetes Mellitus.

OBJECTIVE: Obesity is a state of chronic inflammation that is associated with insulin resistance and type 2 diabetes mellitus (DM), as well as an increased risk of osteoarthritis (OA). This study was undertaken to define the links between obesity-associated inflammation, insulin resistance, and OA, by testing the hypotheses that 1) tumor necrosis factor (TNF) is critical in mediating these pathologic changes in OA, and 2) insulin has direct effects on the synovial joint that are compromised by insulin resistance. METHODS: The effects of TNF and insulin on catabolic gene expression were determined in fibroblast-like synoviocytes (FLS) isolated from human OA synovium. Synovial TNF expression and OA progression were examined in 2 mouse models, high-fat (HF) diet-fed obese mice with type 2 DM and TNF-knockout mice. Insulin resistance was investigated in synovium from patients with type 2 DM. RESULTS: Insulin receptors (IRs) were abundant in both mouse and human synovial membranes. Human OA FLS were insulin responsive, as indicated by the dose-dependent phosphorylation of IRs and Akt. In cultures of human OA FLS with exogenous TNF, the expression and release of MMP1, MMP13, and ADAMTS4 by FLS were markedly increased, whereas after treatment with insulin, these effects were selectively inhibited by >50%. The expression of TNF and its abundance in the synovium were elevated in samples from obese mice with type 2 DM. In TNF-knockout mice, increases in osteophyte formation and synovial hyperplasia associated with the HF diet were blunted. The synovium from OA patients with type 2 DM contained markedly more macrophages and showed elevated TNF levels as compared to the synovium from OA patients without diabetes. Moreover, insulin-dependent phosphorylation of IRs and Akt was blunted in cultures of OA FLS from patients with type 2 DM. CONCLUSION: TNF appears to be involved in mediating the advanced progression of OA seen in type 2 DM. While insulin plays a protective, antiinflammatory role in the synovium, insulin resistance in patients with type 2 DM may impair this protective effect and promote the progression of OA.

Factors Associated With Early Improvement in Low Back Pain After Total Hip Arthroplasty: A Multi-Center Prospective Cohort Analyses.

This study identified factors associated with an improvement in low back pain (LBP) at six-month follow-up after total hip arthroplasty (THA). Data from a national registry of 3054 patients were analyzed. Factors under analysis included demographics, comorbid conditions, operative and nonoperative joint pain severity, physical function, and mental health. Differences in these factors between patients with and without improvement in LBP were examined. Among patients reporting severe or moderate LBP preoperatively, 56% improved 6 months after surgery. Patients without improvement were more likely to be on Medicare, have a high school education or less, have household income less than $45,000 and have one or more comorbid conditions. Patients with improvement in LBP experienced more resolution of pain in both the operative and nonoperative hip.

The prevalence of radiographic criteria of femoral acetabular impingement in patients undergoing hip arthroplasty surgery.

BACKGROUND: Pistol grip deformity of the proximal femur has been reported as a potential cause of hip pain and early-onset arthritis. The exact incidence of patients with osteoarthritis resulting from femoral acetabular impingement (FAI) is unknown. The purpose of this study was to explore the relationship between radiographic markers of FAI in patients undergoing hip arthroplasty. METHODS: We retrospectively reviewed the radiographs of patients undergoing hip arthroplasty by a single surgeon over a 2-year period. The patients were divided by age, those younger than 65 years and (group A) and those 65 years and older (group B). The radiographs were evaluated for morphology consistent with FAI including an α angle >55°, crossover sign, coxa profunda, acetabular protrusio, and ischial spine sign. Three independent reviewers evaluated all the radiographs. The incidence of CAM, Pincer, and mixed deformities were compared between the 2 groups. RESULTS: A total of 255 patients with 258 hip arthroplasties were included in this analysis. Group A was found to have a greater number of patients with CAM morphology. Linear regression analysis revealed that the α angle was greater in younger patients. CONCLUSION: Patients undergoing hip arthroplasty exhibit a high incidence of radiographic abnormalities consistent with FAI. The CAM-type morphology occurs more frequently in younger patients with advanced arthritis requiring hip arthroplasty. This morphology is thought to cause a delaminating injury to the cartilage of the acetabulum. This study supports the notion that CAM-type morphology is a risk factor for early development of degenerative arthritis of the hip.

Imageless computer-assisted versus conventional total hip arthroplasty: one surgeon's initial experience.

Computer-assisted surgery (CAS) systems are advocated to improve component positioning in THA, though potential operative risks and costs of CAS have fueled debate. The present study examines the radiographic outcomes, operative efficiency, cost, and midterm functional outcomes for patients who underwent THA, either with CAS or conventional instrumentation. Patient baseline characteristics were recorded for 126 lower-extremities in the CAS series, and 215 in the conventional series. There was no difference in Harris Hip Score or leg length discrepancy between series. Inclination angle, blood loss, and operating room times were increased for CAS. These results suggest that CAS confers no advantage over conventional methods regarding accuracy of THA component placement, drives unreimbursed increases in procedure costs, may expose patients to additional operative risk, and produces no functional benefit at midterm follow-up.

Hematogenous infection of total hip arthroplasty with Actinomyces following a noninvasive dental procedure.

This article describes a case of an infected total hip arthroplasty following a dental procedure. A 59-year-old man underwent total hip arthroplasty for osteoarthritis and had a routine recovery. Approximately 9 months postoperatively, he underwent a dental cleaning without antibiotic prophylaxis. One month later, he reported gradually worsening right hip pain and a purulent discharge. After several unsuccessful interventions, the patient was referred to the authors' facility. The patient's history, draining sinus tract, and radiographic changes were considered diagnostic of a late chronic infection, and the patient underwent 2-stage revision. Intraoperatively, the sinus tract extended directly to the acetabular component. Actinomyces spp were isolated from 3 of 7 intraoperative anaerobic cultures, and the patient received penicillin G for 8 weeks. Two weeks after discontinuing antibiotics, with no clinical manifestation of recurrent infection and a negative hip aspiration, a new hip prosthesis was implanted. The patient was prescribed penicillin for 12 months postoperatively. Harris Hip Score was 100 at 52-month follow-up. The American Dental Association and the American Academy of Orthopaedic Surgeons issued consensus guidelines for chemoprophylaxis in orthopedic patients undergoing dental procedures in 1997 and 2003. Although the American Academy of Orthopaedic Surgeons issued a revised guideline in 2009 recommending more robust antibiotic prophylaxis, significant controversy exists because at least one professional organization representing dentists has repudiated the 2009 American Academy of Orthopaedic Surgeons guideline. The authors describe the implications from their experience and similar cases in the literature with regard to such guidelines.

Evaluation of donor site intrinsic healing response in autologous osteochondral grafting of the knee.

We report the case of a 45-year-old male patient who underwent autologous osteochondral autografting in the knee for osteochondritis dissecans. The patient required revision surgery 1 year postoperatively, which allowed histologic and mechanical characterization of the intrinsic healing response of the initial graft donor sites. Histologic examination showed heterogeneous areas of dense fibrous tissue, bone, and discrete areas of cartilage. Mechanical testing using a confined compression testing technique determined the equilibrium stiffness as 0.97 MPa. The majority of dense fibrous tissue and areas of bone are likely responsible for the observed increased stiffness. When performing osteochondral autografting, consideration must be given to the benefit afforded to improving the areas of cartilage injury with the potential morbidity associated with graft harvest at the donor sites.